Henry benbow



(No Model.)

H. BENBOW. TUBULAR BOILER.

N0. 484,696. Patented Oct. 18, 1892.

UNITED STATES PATENT ()EEICE.

HENRY BENBOW, OF PLYMOUTH, ENGLAND.

TUBULAR BOILER.

SPECIFICATION formingpart of Letters Patent No. 484,696, dated October 18, 1892.

Ap licati n filed August 29, 1892. Serial No. 444,429. (No model.)

To all whom it mag concern.-

Be it known that I, HENRY BENBOW, chief inspector of machinery, Royal Navy, a subject of the Queen of Great Britain, residing at the Royal Western Yacht Club, Plymouth, inthe county of Devon, England, have invented certain new and useful Improvements in Tubular Boilers, of which the following is a specification.

The ends of the tubes next the combustionchamber are made with a shoulder, which abuts against a seat turned on the inner face of the tube-plate arbrfifilthe hole through which the tube passes. The end of the tube which projects outside the tube-plate is riveted or headed over and preferably fits into a groove in the outer face of the tube-plate. The holes in the other tube-plate are made of sufficient diameter to allow of the shoulders on the tubes to pass through, and the ends of the tubes which fit into these holes are enlarged and are secured either by being expanded into the holes in the usuahmanner and by being beaded over on the outside or by being screwed in. By this construction the ordinary stays, or some of them, may be omitted, for each tube itself forms a stay. The thickness of the combustion-chamber tube-plate may also be reduced.

I provide for the expansion and contraction of boilers, and especially those above described, by forming a groove or corrugation around the combustion-chamber tube-plate beyond the outer row of tubes; or the same result may be attained by a groove or corrugation in the curved side of the combustionchamber itself.

Figure 1 isa longitudinal section of partof one of the tubes, showing its junction with the tube-plate. Fig. 2 is a longitudinal section of part of a double-ended boiler.

A is a portion of the tube-plate; B, the end of tube; 0, a shoulder on the end of the tube, which abuts against a seating formed on the low the lower row of tube-holes.

F is a corrugation formed in the combustionrchamber side plate and extends below the center line of furnaces, or could be continued the Whole length of the plate, with the extreme ends left plain to allow them to be connected together by a riveted joint.

H H is a portion of furnace; J J, a portion of the combustion-chamber, and G G are the ends of tubes inside the boiler.

What I claim is 1. In boilers, the combination of a shoulder near one end of the tube, a seat for the shoulder, formed on the innersurface of the tubeplate around the hole through it, and means for securing the end of the tube to the outer side of the tube-plate.

2. In boilers, the combination of a shoulder near one end of the tube, a seat for the shoulder, formed on the inner surface of the tubeplate around the hole through it, and a groove on the outer surface of the tube-plate, into which the end of the tube is headed.

3. In boilers, the combination of tubes, a tube-plate to which the tubes are rigidly attached, and a corrugation in the tube-plate around the outer row of tubes.

4. In boilers, the combination of tubes, a tube-plate to which the tubes are rigidly attached, and a corrugation in the curved face of the combustion-chamber, extending belowthe lowest tube.

HENRY BENBOYV.

Witnesses:

J. A. VAUGHAN,

Engn, R. N, H ZVI. S. Vim'd. JOHN KEAST,

Writer, R. N., H. 111. S. Vivid. 

